Officers of the police department and such employees as are assigned by the chief of police are authorized to direct all traffic by voice, hand, audible or other signals in conformance with traffic laws, except that in the event of a fire or other emergency or to expedite traffic or to safeguard pedestrians officers and employees of the police department, or members of the fire department, may direct traffic as conditions may require, notwithstanding that provisions to the contrary are contained in this title or the Vehicle Code. (Prior code § 3202)